Not applicable
A computer program listing appendix is incorporated-by-reference. Programs and data, included on xe2x80x9cwrite-oncexe2x80x9d Compact Disc-Recordable (CD-R) discs, operate computer equipment that control, collect, interpret, and print Fluid Energy Pulse Test System data. Two identical CD-R discs labeled COPY 1, created Sep. 18, 2001 and COPY 2, created Sep. 18, 2001 each contain machine language code converted to American Standard Code for Information Interchange code. Each disk contains: [Program FEPTS.ASC for data acquisition, May 2, 2000, 157212 bytes], associated [Data FCOLOR.ASC, Sep. 17, 2001, 84 bytes], and associated [Data EPTS.ASC, Sep. 17, 2001, 57 bytes]; and [Program 2CONTROL.ASC for control sequences, Mar. 8, 2001, 153,393 bytes], and associated [Data COLOR.ASC, May 28, 1999, 149 bytes].
The invention disclosed relates to testing fluid control devices, including pressure sensitive gas-lift valves used to produce hydrocarbons from underground formations, as well as to testing other general types of fluid systems, and more specifically, to test equipment and to test methods that use high-pressure, high-fluid-flow-rate energy pulses to identify fluid performance parameters in order to evaluate the dynamic operating properties of such fluid control devices and fluid systems.
The high cost and complexity of dynamic testing and of evaluating the performance of electro-mechanical, pneumatic, and hydraulic fluid control devices have lead to a rich body of teachings with objectives to reduce the test cost and to simplify the performance evaluations for these devices. However, the cost of dynamic testing to evaluate high-pressure, high-fluid-flow-rate [HPHFFR], pressure sensitive fluid control devices remains high. High pressures and high fluid flow rates occur at fluid pressure above 3,549 kPa (500 psig) and fluid flow rate greater than 0.05663 cubic meters per second (two cubic feet per second). HPHFFR tests are commonly conducted at 6,996 kPa (1000 psig) and 0.14158 cubic meters per second (five cubic feet per second). In some industrial process control areas, such as the production of hydrocarbons, only a sample of a manufacturer""s production run of HPHFFR fluid control devices in service has been tested to determine if all of the devices in that lot can control fluid flow in accordance with the manufacturer""s design parameters. It is well known that dynamic tests should be conducted on all fluid control devices in order to diagnose potential problems prior to their use. If dynamic tests of HPHFFR fluid control devices and fluid systems are not undertaken, diagnosis of problems or potential problems cannot be made.
Limited testing of HPHFFR pressure sensitive fluid control devices is done by device users, manufacturers, and rebuilders. This situation is a direct result of the high cost and technical difficulties associated with the current HPHFFR test environment. Generally, manufacturers"" tests only determine if a HPHFFR device opens, closes, or leaks. The limited number of dynamic tests and performance evaluations of HPHFFR devices is especially notable in the petroleum industry in which such devices are used in the production of hydrocarbons from underground formations. Producing hydrocarbons depends upon many types of pressure sensitive devices, including tubing retrievable or wire line retrievable injection pressure operated gas-lift valves [IPO-GLVs] and production pressure operated gas-lift valves [PPO-GLVs]; differential pressure valves; pilot valves; single- and double-check valves; orifice valves; subsurface safety valves; and subsea gas-lift kill valves. The dimensions of these pressure sensitive fluid control devices include gas-lift valves of varying lengths with outside diameters of 1.5875 centimeters (five-eighths inches), 2.54 centimeters (one inch), and 3.81 centimeters (one and one/half inches); and a variety of larger valves, including 8.89 centimeter (three and one-half inch) diameter subsurface safety valves.
These types of valves are essential to the petroleum industry. The economics associated with gas lift have demonstrated that gas lift technology is competitive with, and in most instances initial costs are less and operating costs are lower than, other types of lift technologies for various types of wells, including deep wells; sand producing wells; high gas-liquid ratio wells; very low capacity stripper wells; wells with changing depths of lift; wells with unknown depths of lift; multi-zone well completions; and wells with large tubing. Gas-lift technology may be the only technology that can be used for the production of petroleum and gas from off-shore platforms. Applications include lifting petroleum until a well is depleted, xe2x80x9ckicking offxe2x80x9d wells that later flow naturally, backflowing water injection and disposal wells, and unloading water from gas wells. Continuous and/or intermittent gas-lift system designs may require many gas-lift valves, for example, twelve valves in a single well.
Historically, the principal reason for the lack of testing and evaluation is the high cost and complexity of test facilities and equipment. Conventional test systems focus upon continuous (also called, steady state or average), fluid flow rate measurement technology. This test technology generates steady state flow data, but requires extensive resources to build and to operate HPHFFR test facilities. As a result, testing pressure sensitive fluid control devices with continuous flow test technology is very expensive.
Previous investigators have approached the problems of testing fluid control devices dynamically in a number of ways, several of which are briefly discussed. For example, U.S. Pat. No. 5,616,824 to Abdel-Malek et. al. (1997), teaches a valve diagnostic system for installed electromechanical control valves. The system identifies and compares to file data, a time-signature of valve operation to detect or predict potential valve failure. U.S. Pat. No. 5,524,484 to Sullivan (1996), teaches a diagnostic system for solenoid valves that are installed in line and which are in service. U.S. Pat. No. 5,329,956 to Marriott (1994), teaches a method of time signature analysis for electrically actuated, pneumatically controlled valves. U.S. Pat. No. 5,197,328 to Fitzgerald (1993), teaches a diagnostic method for pneumatically operated control valves. U.S. Pat. No. 5,272,647 to Hayes (1993), teaches a portable device that perturbs a valve actuator and monitors valve stem displacement, actuator pressure, and other valve parameters for steady state flow conditions. U.S. Pat. No. 4,903,529 to Hodge (1990), teaches a method and apparatus to analyze a hydraulic control valve and actuator assembly during plant shut-down periods. U.S. Pat. No. 4,893,494 to Hart (1990), teaches a method to evaluate safety valves removed from an installation by using either pneumatic or hydraulic fluids. U.S. Pat. No. 4,464,931 to Hendrick (1984), addresses steady state dynamic valve testing with an apparatus that checks a valve calibration (closing) pressure, checks valve closing integrity, and checks valve flow rate at a pressure greater than the valve calibration pressure.
The concept of a pressure pulse is derived from unsteady fluid flow and the propagation of large amplitude nonlinear waves, from which shock waves can be generated as a result of the physical attributes of non-steady-state fluid flow. An initially continuous waveform that advances into a uniform, stationary fluid is termed a pressure pulse. Pressure pulses are referenced in U.S. Pat. No. 4,549,715 to Engel (1985), which teaches an apparatus to generate gaseous pressure pulses to rapidly open an exhaust path to create a high volume, low pressure pulse. U.S. Pat. No. 4,686,658 to Davison (1987), teaches an apparatus and method for actuating a valve for imparting pressure pulses in a pressure pulse telemetry system wherein the actuating force is adjusted in response to a measured value of the minimum force necessary to actuate the valve. This provides a self-adjusting actuator to reduce the power needed to actuate the valve, prolong battery life in the associated batteries, and prolong valve and circuit life. And, U.S. Pat. No. 5,176,164 to Boyle (1993), teaches a flow control valve system for a hydrocarbon-producing well using gas-lift technology, in which the orifice size of a down-hole valve is electrically or pressure pulse controlled from the surface. The fluid flow rate through the valve is controlled over a continuous range, keeping the orifice size constant when necessary. Valve orifice size and well conditions are monitored down-hole and transmitted to the surface as feedback signals for valve control.
These references illustrate that testing electrical, hydraulic, and pneumatic control devices dynamically has been considered, and that pulse pressure systems have been used for certain types of process control systems. However, previous work and reference documentation have not addressed the development of energy pulses and transient states of pressure, temperature, and fluid flow rate for testing and evaluating HPHFFR fluid control devices and fluid systems. As a result, no economical equipment and methods are available to perform dynamic tests and evaluations of fluid control devices such as gas-lift valves. This situation exists because prior technology is based upon continuous flow principles which require costly facilities and equipment.
The concept of an energy pulse as defined for the described invention is derived from the kinetic energy in non-steady fluid flow and the propagation of large amplitude nonlinear waves, in which a wave""s kinetic energy is a function of fluid density and the square of wave velocity. In testing fluid control devices and fluid systems with energy pulses, test criteria and procedures require consideration of the potential effects of kinetic energy on the tested fluid control device or fluid system.
Testing and characterizing the parameters of fluid control devices include techniques, methods, and equipment derived from mathematical physics, fluid dynamics, gas dynamics, aerodynamics, and thermodynamics. In the classical context, all HPHFFR technology is restricted to following the laws of the thermodynamic equations of state, conservation of energy, conservation of mass, and conservation of momentum. Practical efforts to apply the equations of physics that manifest the physical content of these laws for economical testing protocols have proved to be quite difficult. Problems associated with evaluating fluid control devices using compressible gases are most complex. As a result, experimental methods are coupled with well known empirical equations to provide reasonably accurate data which describe the dynamic properties of fluid control devices. The principal device parameters for which performance measures are desired are upstream pressure, downstream pressure, fluid temperature, and fluid flow through the device.
In practice, fluid pressures are readily determined by conventional pressure transducers and fluid temperatures are measured by conventional temperature transducers that are appropriately protected from fluid abrasion and fluid forces. Fluid flow is more demanding and more difficult to measure, especially for pressure sensitive fluid control devices that are activated by compressible fluids. In practice, in the absence of a calibrated direct measuring flowmeter with appropriately conditioned fluid flow profile, one approach to determining flow through a flow control device is based upon a flow coefficient for a device under test. A flow coefficient is a measure of the ability of the device to permit (or to restrict) flow and this coefficient must be empirically determined for each kind of fluid control device. The coefficient is defined to vary between zero and one. The coefficient is one of the terms in an empirical equation, of which there are many. The coefficient, along with pressure, temperature, specific gravity, and device-geometric dimensions, is used to calculate, at a variety of pressures and device geometries, the steady state fluid flow through the device under evaluation. A calibrated flowmeter transducer to measure continuous flow HPHFFR fluids, especially compressible fluids, can also be used for measurement and in practice various transducers have been used for continuous fluid flow measurements. Mass fluid flow rate calibration is achieved, for example, by using precisely manufactured fluid flowmeter runs and/or fluid flow conditioners to generate a uniform fluid flow profile within a pipe. Thereafter, the fluid is delivered into a calibration vessel and the fluid is weighed over time. Mass fluid flow rate can be converted to volumetric fluid flow rate by standard fluid flow conversion equations.
However, there are a number of problems associated with fluid flow test measurements in steady state HPHFFR systems. First, from an economic standpoint, the cost of continuous flow HPHFFR testing of fluid control devices and fluid systems is high because of large compressors, high-volume storage systems, high maintenance, and, especially, high operating costs. Second, from a technical standpoint, different steady state flow rates must usually be measured to adequately determine the performance of a device under test. This requires multiple tests and increases operating costs. Third, in HPHFFR systems the installation and removal time for a fluid control device to be tested may be long, difficult, and costly. Fourth, the dynamic response of flowmeters may not be sufficiently fast to capture flow variations resulting from energy transient flows. Fifth, an installed flowmeter may generate excessive backpressure upstream of the flowmeter and lower pressure downstream of the flowmeter, depending upon the flowmeter physical properties. The generation of backpressure may be difficult to eliminate or to reconcile for pressure sensitive fluid control devices.
As a result of the many problems associated with testing HPHFFR fluid control devices, especially the problem of high cost, these devices commonly are not tested. Consequently, with a need for information that defines the operation of HPHFFR devices such as gas-lift valves, experimental testing and mathematical formulae, correlated with a series of live-device performance tests are conducted to achieve xe2x80x9cbenchmarkxe2x80x9d criteria for a single device to which all similarly manufactured HPHFFR devices are assumed to match. Such benchmark criteria fall far short of practical experience. For example, oil-field production tests have been used to evaluate partially the performance of gas-lift valves. Practice indicates that several gas-lift valves of the same manufacture, which are assumed to meet a benchmark criteria, may not have the same performance characteristics. Thus, engineers who design gas-lift valve lifting programs for on-shore and off-shore hydrocarbon production must include design parameter variations to accommodate up to xc2x130 percent error in characterizing the performance of a single gas-lift valve. This substantial level of error, documented by extensive tests conducted by the University of Tulsa Artificial Lift Projects (reference API 11V2, xe2x80x9cRecommended Practice, Gas-Lift Valve Performance Testingxe2x80x9d, Jan. 13, 1992) and requiring approximately six hours to complete the characterization of a single gas-lift valve, is generally known in the petroleum industry. This substantial level of error for a single valve characterization can translate to a much larger error, reportedly up to 200 percent, in the design of a valve string with many valves. However, the objective is to get an oil well that is producing under gas lift to flow, even if the gas-lift valve string design is substantially sub-optimal. Yet, it is well known that gas-lift valves operating at optimal design parameters produce more hydrocarbons at lower production cost.
The complexity and cost associated with testing gas-lift valves have generated two industry responses. The first industry response was initiated by the American Petroleum Institute [API] which established a working committee, designated the 11V2 Work Group, within the area of artificial lift technology, to create a standard for testing a benchmark valve of a given manufacture. After fifteen years of effort, the API issued the publication, xe2x80x9cRecommended Practice 11V2, Gas Lift Valve Performance Testing, 1st Edition, 1995, partly based upon the draft API 11V2 xe2x80x9cRecommend Practice Gas-Lift Valve Performance Testingxe2x80x9d, Jan. 13, 1992. The API gas-lift valve test procedures are also represented in the specification of U.S. Pat. No. 5,107,441 to Decker (1992), assigned to Otis Merla Corporation. The methods taught in U.S. Pat. No. 5,107,441 are designed to predict flow rate performance characteristics of valves, including gas-lift valves, with a minimum of actual testing. The predicted valve flow rate is based upon the practice of describing the performance of a benchmark valve to which all other valves of the same manufacture are assumed to conform. U.S. Pat. No. 5,107,441 also instructs that determining the flow coefficient for pressure sensitive gas-lift valves is insufficient to accurately predict valve performance. Further, the patent teaches that the correlation of test data to actual flow measurements requires multiple live-valve performance tests at pressures close to expected operating pressures in order to determine if the correlated data are close to the actual data. Thus, these teachings require multiple live-valve tests to be performed on a benchmark valve.
The second industry response is a result of the international petroleum industry""s need for dynamic test and performance data for gas-lift valves used in hydrocarbon production. A number of companies, including BP Exploration Operating Company, Chevron Petroleum Technology Center, Edinburgh Petroleum Services, and Shell International E and P joined to form a consortium called the Valve Performance Clearinghouse [VPC]. The VPC performs dynamic testing and performance evaluations for specific benchmark gas-lift valves and provides these data to the petroleum industry. Only six such benchmark valves had been tested as of April 1998.
Historically, the evaluation of a fluid system""s performance is characterized by the accuracy of fluid flow rate measurements. Standards of fluid flow rate accuracy such as those provided by the API, the American Gas Association, and the International Standards Organization, include calibration techniques and pipe configurations that are based upon the accuracy of optimal flow profiles, of flow conditioners, and of meter runs, all of which attempt to measure steady state flow rates accurately. Steady state measurement is the dominant approach to evaluating fluid flow in fluid systems.
In fluid dynamics, the law of similarity assumes that flowmeter calibration factors, sometimes called empirical discharge or flow coefficients, are valid only when geometric and dynamic similarity exists between the metering and the calibration conditions, or between metering and empirical data conditions. Under these conditions of fully developed flow, the flow measuring device is assumed to accurately measure the true flow rate. In practical installations, the velocity profile of the fluid flow is distorted by swirl and upstream and downstream pipe fittings and configurations. Various methods are used to eliminate these problems including flow conditioners and xe2x80x9cmeter runsxe2x80x9d which are straight lengths of pipe before and after the flow measuring device to isolate the flowmeter. The desired flow conditions for meter runs are a swirlfree, axis-symmetric, time averaged, velocity profile. These desired conditions further demonstrate that current flow measuring technology is centered upon flow profiles that exist in a thermodynamic steady state condition of flow. This emphasis on steady state and therefore average flow measurement is well known in fluid dynamics.
In a practical industrial environment, there are many situations in which fluid flow rate data are needed but pipe configurations do not permit meter runs. There are also situations in which fluid flow rate information is needed on transient fluid flow rate. Mechanical flowmeters such as turbine and target flowmeters cannot be used to measure high fluid flow rate transients, because the inertia of internal components cannot follow fast transients, and flowmeter targets obstruct flow. Further, practical problems can exist when flow rate is measured by a flowmeter device that generates excessive backpressure. There are obstructionless flowmeters for magnetic fluids and obstructionless ultrasonic and tracer-particle flowmeters for other fluids. These flowmeters may not be practical for general testing because testing with magnetic and tracer-particle fluids is expensive and ultrasonic flowmeters may be too large to be installed in the confined spaces of testing equipment.
The use of a critical flow nozzle [CFN] for fluid flow measurement serves as a solution to these problems. If a CFN throat diameter is sufficiently larger than the largest fluid control orifice of a tested fluid device or fluid system, the CFN is nearly obstructionless with respect measured flow. Expanding fluid entering such a CFN generates low backpressure that can be less than five percent of the testing fluid pressure.
Current efforts to measure and record dynamic test data, and to evaluate HPHFFR fluid devices and fluid systems economically, suffer from many disadvantages.
(a) The accepted industry standards for determining the fluid flow rate through a fluid control device are based upon the physics of steady state flow. In gas flow systems, steady state flow is measured because of presumed difficulties in evaluating transient compressible fluid flow practically. Problems associated with measuring transient compressible flow are exacerbated by high pressure and high flow rate compressible fluids. Thus, transient compressible fluid flow is seldom measured or used in fluid test equipment to test and evaluate fluid control devices or fluid systems.
(b) For gas-based systems, HPHFFR continuous flow systems requires large compressors and large pneumatic storage facilities to maintain a continuous HPHFFR.
(c) Personnel requirements and HPHFFR maintenance increase costs.
(d) HPHFFR compressor and compressible fluid storage facilities require large land areas and/or buildings to accommodate equipment.
(e) HPHFFR testing usually involves xe2x80x9cdelay timexe2x80x9d for compressors to build up stored energy to conduct tests, thereby increasing personnel costs as personnel wait for the equipment to reach operating pressure to generate operating flow conditions.
(f) Current testing facilities use large capacity fluid systems to match, or to approximate, real world operating conditions for the device under test. Personnel safety requires that the design and fabrication of such HPHFFR systems exceed the expected operating conditions of testing. HPHFFR system cost increases appreciably as the size and maximum pressure of a HPHFFR system increases.
(g) The high cost associated with testing HPHFFR devices generates an environment in which manufacturers and rebuilders of these devices do not perform routine dynamic performance tests to determine if a manufactured or rebuilt device can control fluid flow. Furthermore, the tests that are conducted by manufacturers only determine if a flow control device opens, closes, or leaks. These current tests cannot determine if a flow control device""s dynamic performance is capable of controlling the fluid flow through the device. The expected performance of the device is based upon design parameters, not upon tests.
(h) Newly manufactured, rebuilt, or used flow control devices such as gas-lift valves, that assist in the recovery of hydrocarbons, and which also assist in the disposal of waste in fluid disposal wells, are not routinely evaluated for performance by manufacturers or by users.
(i) There are only a few facilities in the world that can evaluate the HPHFFR performance of fluid control devices such as gas-lift valves. Two of these facilities are in the United States: Southwest Research Institute, San Antonio, Tex., and the University of Tulsa Artificial Lift Project facility, Tulsa, Okla. The University of Tulsa cannot evaluate gas-lift valves for commercial purposes. The cost to rent facilities at Southwest Research Institute exceeds $12,000 to test a single valve that may cost $750 or less. Additional fees are required for correlating the test data. High costs cause only one benchmark valves to be tested. Thus, users of new or rebuilt gas-lift valves do not know if their valves are defective.
(j) Currently, only benchmark HPHFFR devices such as gas-lift valves are evaluated to determine their performance characteristics. All valves of the same design, both newly manufactured and rebuilt, are assumed to perform to the same standards as the benchmark valve. Yet, it is well known in the petroleum industry that all gas-lift valves of the same design and construction do not have the same performance characteristics because of conditions, such as, different manufacturing tolerances, different environmental conditions, damage to internal components, age, and new, used, or remanufactured condition.
(k) Knowledge of the reasons for the failure of a producing hydrocarbon well is critical to improving hydrocarbon production. Yet, when a well that uses gas-lift valves undergoes a workover to bring the well back on-line after a failure, no existing economic technology is available to determine if the problem occurred because of the hydrocarbon producing formation or because of a failed or improperly operating gas-lift valve. When gas-lift valves are retrieved from a well, they are returned to a manufacture for rebuilding, or in some cases, discarded. They are not evaluated for failure. They are not returned to the well for production. Performance tests are not conducted on the removed gas-lift valves to determine if one or more of them failed or materially contributed in some other way to the failure of the well.
In accordance with the principles of the disclosed invention herein designated Fluid Energy Pulse Test System [FEPTS], there are provided:
(a) an apparatus, to conducts dynamic testing of fluid control devices or fluid systems using HPHFFR or low-pressure, low-fluid-flow-rate energy pulses;
(b) a first method, to test fluid control devices or fluid systems to generate dynamic test data from an open- or a partly-open-to-the-atmosphere system;
(c) a second method, to test fluid control devices or fluid systems to generate dynamic test data from a closed-to-the-atmosphere system;
(d) a third method, to evaluate open-, or partly-open-to-the-atmosphere system dynamic test data to determine dynamic performance characteristics of tested fluid control devices or fluid systems;
(e) a fourth method, to evaluate closed-to-the-atmosphere system dynamic test data to determine dynamic performance characteristics of tested fluid control devices or fluid systems; and,
(f) a fifth method, to evaluate power and energy use of tested fluid control devices or fluid systems.
My FEPTS uses HPHFFR energy pulses that are a fraction, one-half of one-percent or less, of the amount of energy required for current steady state testing of fluid control devices and fluid systems. Using HPHFFR energy pulses, the FEPTS generates a range of economical test procedures and results that permit evaluation of open-, partly-open-, or closed-to-the-atmosphere test data, that characterize the performance and dynamic properties of fluid control devices and fluid systems.
The apparatus comprises a plurality of fluid storage tanks separated into one or more main reservoir tanks, one or more upstream reservoir tanks, and one or more downstream reservoir tanks; a system to fill the main reservoir storage tanks with fluid; a system to transfer fluid from the main reservoir tanks to upstream reservoir tanks and to downstream reservoir tanks; a secondary receiving fluid system that may be a test chamber containing or not containing a fluid control device, or another fluid system; a plurality of fast acting solenoid and electro-pneumatic control valves to deliver high pressure, high fluid flow rate controlled energy pulses to the secondary receiving fluid system; a plurality of fast acting solenoid and electro-pneumatic control valves to exhaust high pressure fluid from the secondary receiving fluid system; fluid path configurations that permit opening or closing of the fluid flow to the atmosphere; a plurality of fluid metering valves, also described as fluid flow set valves, with fine fluid control capability to assist in controlling energy pulses that deliver energy to the secondary receiving fluid system; a plurality of transducers to measure fluid temperature, main reservoir fluid pressure, upstream reservoir fluid pressure, downstream reservoir fluid pressure, upstream and downstream (of tested device or system) fluid pressure, differential fluid pressure, and fluid flow rate; electrical signal conditioning equipment; analog to digital conversion equipment; a plurality of power supplies so that electrical power supplied to transducers is separate and distinct from electrical power supplied to control and metering valves; remote control transmitters and receivers; one or more computers to receive test data and to control the parameters and the timing of energy pulses for testing; a monitor and printer to display and print test data and test results; and, if more than one computer is used, a switch to shift from one computer to the other while computer programs are running.
The methods are:
A first method to test a fluid control device dynamically in order to acquire open- or partly-open-to-the-atmosphere test data comprises the following steps: selecting a fluid exhaust path that is open- or partly-open-to-the-atmosphere; establishing secondary receiving fluid system upstream and downstream initial pressure conditions; generating one or more energy pulses having controlled pulse strength, pulse duration, pulse frequency, and pulse delay; sending one or more controlled energy pulses to the secondary receiving fluid system; and recording data.
A second method to test a fluid control device dynamically in order to acquire closed-to-the-atmosphere test data comprises the following steps: selecting a fluid exhaust path that is closed-to-the-atmosphere; establishing secondary receiving fluid system upstream and downstream initial pressure conditions; generating one or more energy pulses having controlled pulse strength, pulse duration, pulse frequency, and pulse delay; sending one or more controlled energy pulses to the secondary receiving fluid system; generating one or more exhaust energy pulses having controlled pulse strength, pulse duration, pulse frequency, and pulse delay; sending one or more controlled exhaust energy pulses to the atmosphere from the upstream and/or downstream secondary receiving system; and recording data.
A third method to evaluate open- or partly-open-to-the-atmosphere system dynamic test data to determine dynamic performance characteristics of a tested fluid control device comprises the following steps: rendering dynamic test pressures, temperatures, and flow rate data as a function of time; parametrically rendering upstream reservoir pressure, upstream and downstream pressure (of the tested device or system), and/or temperature as a function of fluid flow rate; determining if time-dependent dynamic test data and the parametric rendering of these data meet an acceptable degree of open-system dynamic performance, as determined from design specifications or historical records; and, when required, using the acquired data to design, or to evaluate the design of, a field-operating system that uses the tested device.
A fourth method to evaluate closed-system dynamic test data to determine dynamic performance characteristics of a tested fluid control device comprises steps: rendering closed system dynamic test pressures, temperatures, and flow rate data as a function of time; parametrically rendering upstream and downstream pressure (of the tested device or system) and/or temperature as a function of fluid flow rate; and determining if time-dependent closed system dynamic test data and the parametric rendering of these data meet an acceptable degree of closed-system dynamic performance, as determined from design specifications or historical records.
A fifth method to evaluate power and energy use of a tested fluid control device comprises steps: determining power supplied to and power delivered by a fluid control device as the multiplicative result of a pressure and a fluid flow rate; rendering power supplied and power delivered as a function of time; determining energy supplied to and energy used by a fluid control device by the integration with respect to time of power; and determining if these data meet an acceptable degree of performance, as determined from design specifications or historical records.
Accordingly, objects and advantages of the FEPTS are:
[1] to reduce the amount of energy, capital, maintenance, personnel, and other costs of acquiring test data and of evaluating a fluid control device or fluid system dynamic performance characteristics under varying operating conditions;
[2] to provide an apparatus that uses transient HPHFFR energy pulses to generate temperature, pressure, and fluid flow rate dynamic test data for fluid control devices and fluid systems;
[3] to provide an apparatus that incrementally controls high-energy pulses from zero energy to maximum energy delivery, so that a fluid control device or fluid system can be tested without damaging the device or system;
[4] to provide an apparatus that eliminates the long delay time required for large compressors and large gas-storage systems to build sufficient energy to conduct dynamic tests of fluid control devices and fluid systems;
[5] to provide an apparatus that permits a fluid control device test chamber, or a fluid system, to be connected to the apparatus in order to test dynamic performance characteristics;
[6] to provide an apparatus that is relatively light in weight, compact, and small in comparison to existing steady state dynamic test equipment;
[7] to provide an apparatus that uses a small compressor and small fluid storage tanks;
[8] to provide an apparatus that can receive stored energy from multiple energy sources, including fluid storage tanks or bottles, compressors, and, if safety measures are met, from natural gas wells and pipelines;
[9] to provide an apparatus that can be operated by one person;
[10] to provide an apparatus that generates, from a HPHFFR or a low-pressure, low-fluid flow rate energy source, energy pulses with controlled pulse strength, pulse duration, pulse frequency, and pulse delay;
[11] to provide an apparatus that exhausts, from a pressurized fluid control device or system, energy pulses with controlled pulse strength, pulse duration, pulse frequency, and pulse delay;
[12] to provide an apparatus that controls energy pulse strength by a metering valve and a pulse valve in series communication, in which the metering valve has fine control of fluid flow that is achieved by either a continuous or stepping electric motor drive and reduction gears, and in which the pulse valve has bang-bang control achieved by solenoidal or electro-pneumatic control (bang-bang defines on-or-off condition only);
[13] to provide an apparatus that is controlled by one or more computers, which initiate a test sequence, pressurize components, control metering valves, control pulse valves, exhaust fluid, sequence the time of fill, pulse, and exhaust valves, collect transducer data, render test data into graphs, compute and graphically render power and energy use, stop a test sequence, and provide memory for pre-specified tests in order to reproduce identical test sequences, store test data, store historical records, and generate reproducible results from dynamic tests of fluid control devices and fluid systems;
[14] to provide an apparatus for testing HPHFFR devices and systems that promotes an environment in which manufacturers, re-builders, and users of fluid control devices can conduct routine dynamic tests of the devices to ensure quality control and acceptable device performance;
[15] to provide an apparatus for testing economically each and every new, used, or rebuilt fluid control device, including gas-lift valves employed to produce hydrocarbon products, after manufacture, at sale, after shipping, before entering a well, upon retrieval from a well, before rebuilding, and after rebuilding;
[16] to provide an apparatus and methods that define the dynamic performance characteristics of a fluid control device or fluid system by tables and graphs, which information can follow a device or system throughout its useful life;
[17] to provide an apparatus with a HPHFFR test chamber that permits individual fluid control devices of various type and manufacture to be installed in and removed from a test chamber in seconds;
[18] to provide an apparatus and methods which can increase the number of facilities throughout the world that are capable of testing and evaluating the dynamic performance characteristics of fluid control devices and fluid systems, because the apparatus and methods can significantly reduce their cost and complexity;
[19] to provide an apparatus and methods that produce an alternative to the current equipment and methods of characterizing the performance of flow control devices, such as gas-lift valves, through expensive xe2x80x9cbenchmarkxe2x80x9d tests of a single device, which all other devices of the same manufacture are then assumed to match;
[20] to provide an apparatus and methods to assist in determining the cause of shut-down of a producing hydrocarbon well, when hydrocarbon production is lifted by gas-lift valves that may have failed or become defective;
[21] to provide an apparatus that can generate controlled backpressure on fluid control devices and fluid systems, so that testing and evaluating such devices and systems under various backpressure conditions can be achieved;
[22] to provide an apparatus for HPHFFR systems that can maintain, for a reasonably short dynamic testing period, pressure within a test chamber or a fluid system, which pressure is within pressure boundaries, by generating a positive (high pressure) energy pulse to achieve fluid flow into the chamber or system, and, simultaneously, generating a negative (exhaustive) energy pulse to a lower pressure or to the atmosphere, which removes fluid from the chamber or system;
[23] to provide a method to evaluate open- or partly-open-to-the-atmosphere dynamic test data for a fluid control device or fluid system by rendering the temperature, pressure, differential pressure, and fluid flow rate data as a function of time, and by rendering the pressure and/or temperature data parametrically as a function of flow rate, in order to identify, evaluate, and diagnostically check basic dynamic performance parameters of the device or system;
[24] to provide impulse-type, short duration energy pulses, generally less than one-half second duration, which generate impulse-type response test data;
[25] to provide energy pulses, with durations longer than one second, that generate step, ramp, and/or steady state or near steady state response characteristics, wherein an operator chooses pulse parameters to generate impulse, step, ramp, and/or steady state or near steady state response characteristics, which response characteristics are a function of the flow capacity of the fluid control device or fluid system under test;
[26] to provide a method to generate a frequency response for a fluid control device or fluid system from a multiplicity of energy pulses with identical periods and decreasing amplitude, in order to identify, evaluate, and diagnostically check dynamic performance parameters, such as, opening pressure when fluid flow starts, closing pressure when fluid flow stops, and fluid flow rate of the device or system under test;
[27] to provide a method to use slowly increasing pressure and/or slowly decreasing pressure impressed upon or released from a fluid control device or fluid system in order to evaluate dynamic performance parameters when the system is closed-to-the-atmosphere; and, [28] to provide a method to evaluate power and energy associated with the dynamic operation of a fluid control device or fluid system, when such power and energy are derived from test data generated by impulse, step, ramp, and/or frequency input functions.